Maximal 12-lead exercise testing for prediction of severity of coronary artery disease.

Ninety-three patients with chest pain underwent both maximal 12-lead treadmill testing and coronary arteriography to ascertain whether exercise testing might predict multivessel coronary disease. Twenty-eight patients had normal coronary arteries, 20 single vessel disease (greater than 70% reduction in luminal diameter), 18 double and 22 triple vessel disease. Five patients had left main coronary disease. All 45 patients with double, triple or left main disease had positive 12-lead exercise tests whilst only 15/20 (75%) with single vessel disease had positive tests. Sensitivity of the 12-lead electrocardiogram during maximum stress testing was 92%, with 15% false negatives. The predictive value of a positive test was 100% (no false positives) and 85% for a negative test. Significant predictors of severe triple vessel and left main coronary disease were the sum of ST segment depression (xi ST), the number of ECG leads which developed ST segment depression, the stage at which ST depression developed and the ST segment recovery time. There was a significant correlation between the anatomical location of coronary artery stenoses and the area of ischaemia indicated by the exercise electrocardiogram.